


Bonds of Blood and Duty

by WotanAnubis



Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Vampire, Ashen Demon, Blood Drinking, F/F, Lesbian Vampires, Pre-Time Skip, Vampire Byleth
Language: English
Status: Completed
Published: 2019-10-13
Updated: 2019-10-13
Packaged: 2020-12-14 12:21:10
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,777
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21015689
Author URL: https://archiveofourown.org/users/WotanAnubis/pseuds/WotanAnubis
Summary: In which Rhea takes responsibility for what she's done to Byleth.





	Bonds of Blood and Duty

**Author's Note:**

> There may be some Frankenstein parallels here. But with less hideously stitched-together corpse monsters and more sexy vampires.

"Mother?"

Rhea jolted upright in the utter dark of her bedroom. Her breaths were quick and shallow, her body drenched with sweat. There were... images... in her mind. Nightmares she couldn't remember, only fear.

"No."

Rhea took a sharp breath. Someone was here. _Here_. In the heart of Garrech Mach, in her very own bedroom. It shouldn't be possible. She leaned back slightly, her right hand moving across the sheets to the dagger under her pillow.

Two red points of light blazed in the darkness and a figure stepped from the shadows into the moonlight.

Rhea relaxed, and smiled.

"Ah, Professor. It's only you," she said.

"Yes," said Byleth. "I'm sorry if I startled you."

"No, no, it's..." Rhea stopped. "What are you doing here? How did you get here?"

Byleth came closer, sat down on Rhea's bed. It was an insolent, familiar gesture. Rhea would have called the guards and have Byleth executed were she anyone else. However, she was Byleth, and, really, was it so extraordinary for her mother to come visit her when she had nightmares?

"You'd be surprised at all the places I can get into," said Byleth. "As for what I'm doing here... that may take some explaining. How much do you know about my mercenary days?"

"Almost nothing, I'm afraid," Rhea replied. "Jeralt is reluctant to tell me anything and avoids my questions and as for you... Well, I feel you should not trouble yourself about the past and focus on what's to come."

"I think you should trouble yourself about my past."

Byleth turned to look out the window, seemingly wondering what to say next. Her skin was deathly pale in the moonlight and there was a reddish hue to her eyes.

"You've heard of my nickname?" Byleth said.

"Dear child, before now I wasn't even aware you had a nickname."

Rhea found herself relaxing and leaned back against her pillows. She wasn't at all sure why Byleth had chosen this moment to come tell her stories, but she was going to object. It was no doubt the influence of her mother lurking in her heart and in her blood that drove Byleth to become closer to her. If it was in something of an... unconventional way.

"The Ashen Demon," said Byleth. "That's what everyone called me. My father never did, but the mercenaries in our company did. I didn't remember exactly when I got the name. Time's never had much meaning to me. But I remember the circumstances.

"It was just another job, really. Some bandits were causing trouble and some noble paid us get rid of them, because he couldn't be bothered to do it himself. There weren't that many of them, and they weren't that skilled. By the time there were only a few of them left, one of them was so desperate, they rushed at me with all their strength. I managed to block the blow easily, but the force of the attack broke my blade. So there I was, suddenly unarmed and faced by a bandit who suddenly had the upper hand."

"But you are here, and they are not," said Rhea. "So I must assume you overcame them yourself."

"Oh, yes," said Byleth. "Something... took over. Something dark, and feral. I lunged at the bandit, drove them to the ground, and sank my teeth into their neck."

Rhea blinked. "What?"

"I gorged myself on that bandit's blood," Byleth said dreamily. "In hindsight, it was fouled by drink and disease, but it was the first time I'd tasted. When that warm blood passed my lips I felt... ecstatic. More than that, I _felt_. While I was latched on to that filthy neck, I finally understand all that poetry and all those songs. For the first time in my... existence... I was alive."

A cold, terrible shiver ran down the back of Rhea's spine. "No," she whispered. "No, that, that wasn't supposed to happen."

Byleth looked at her, and the red gleam in her eyes was terrible.

"I've been the Ashen Demon ever since," Byleth continued. "The pale monster that spread suffering and death on the battlefield. After I drank that bandit's blood, my father decided to tell me everything. I was furious. And I was delighted at being able to be furious."

"What..." Rhea began, dreading to ask the question on her lips, "what did Jeralt tell you?"

"That I was dead," Byleth stated plainly. "And that you did something to me to save me. But that it didn't really work. My heart still doesn't beat. Blood doesn't flow through my veins. I'm not dead, but neither am I alive."

"I did save you," Rhea said. "But Jeralt doesn't know the full story."

"No? Then what is the full story?"

Rhea faltered. What could she say? That she hadn't intended to save Byleth? That Byleth's life was temporary thing loaned to her, and that she intended to snuff out? That Byleth was only a vessel to allow for her mother's rebirth?

It did not seem wise to tell her any of that. Not when they were alone in her bedroom in the middle of the night while Byleth looked at her with those hungry red eyes.

"You were... an experiment," said Rhea. "But unfortunately, Jeralt stole you away from me before it could come to fruition."

Byleth looked at her in silence for too long, head tilted slight to one side. It took quite a lot of Rhea's willpower not to squirm under her gaze. Which was ridiculous. She had seen centuries, whereas had lived for only a scant few decades. Had, perhaps, not lived at all. What was there to fear of her? What was there to be ashamed of?

"I see," Byleth said at last. "And what did you hope to accomplish with this... experiment?"

"To restore someone to life, of course," Rhea replied.

"You failed. I am stuck in twilight," said Byleth. "But there is something you can do to help me."

"You..." Rhea's voice faltered, the words stuck in her dry throat. She took a deep breath. "You want my blood."

Byleth reached out for her and twisted a strand of Rhea's green hair around her pale finger. "Not all of it. Just enough to restore me to life. For a while."

Rhea had never heard such a brazen request, and yet she didn't feel angry. Couldn't. The woman sitting on her bed, shamelessly playing with her hair, was not her mother. Would never be her mother. So who, then, was she?

More importantly, did she owe her anything? Did she owe her blood? Byleth - this pale fiend - was a creature of her own making. And for so long as she was Byleth, and not Sothis, should she not, perhaps, take some responsibility for her?

"And if I refuse?" said Rhea.

"I'll find my blood elsewhere," Byleth said.

Enemies? The knights, the other teachers, the _students_? No. She could not allow that. Byleth was her creation, so it was her duty to care for her.

"That won't be necessary," Rhea said. "You can taste of my blood. On one condition."

"Name it."

"It is _only_ my blood you will drink."

Byleth smiled. Her teeth were disturbingly white in the moonlight, and Rhea noticed how long and sharp her canines were. Odd that she hadn't spotted that before now.

"Very well."

Byleth crawled up Rhea's moonlit bed until she loomed over her. Rhea shivered to see her, the cruel triumph of her thin smile, the urgent thirst in her red eyes. And yet it wasn't fear she felt, nor revulsion. This... _thing_... hungered openly for her blood, and yet...

Byleth leaned in, lips drawn back. Rhea grunted when she felt those sharp teeth pierce her skin, like two shards of ice sinking into her veins.

There was pain, yes, but it was brief, and what followed was... She didn't know what it was. Her warm blood flowed from her neck past Byleth's lifeless lips, and with every drop that left her, she felt...

Byleth moaned softly against her pierced, bloody skin. Rhea gasped when she heard it, felt a stab of heat through her body even as the creature lying on top of her drained her of her warmth drop by drop.

Without knowing why, Rhea embraced Byleth and held her close to her neck. This sacrifice of blood... it was more than merely a sacrifice. She felt as if it was...

Rhea's breath became shallow gasps. She was getting light-headed. And yet she clutched Byleth to herself. She didn't know how much blood she'd lost, and didn't care. So long as Byleth still thirsted for her blood, she could drink her fill. And with every drop that left her veins, with every red mouthful Byleth greedily swallowed, they...

Byleth pulled away from Rhea's neck, easily breaking the Archbishop's embrace. Her white teeth were stained red and rivulets of blood ran from the corners of her mouth. When she looked down at Rhea, her red eyes were filled with a hunger of a different kind.

Byleth leaned down to kiss Rhea. Her lips were cold and foul with the iron taste of blood. And yet Rhea returned her kiss without thinking, without worrying about the fact it was her own blood she tasted on this dead creature's lips.

She did not understand what had happened this night. Probably would not for a long time. But if Rhea was sure of anything, it was that she and Byleth were bound together now. Not simply by the soul of Sothis lurking in Byleth's silent heart, but by the ties of her own blood.

Rhea did not know what this meant for them. What they now were to each other. But right now, in this moment, it was enough for her to feel Byleth's blood-stained lips kissing her own.

"Thank you," Byleth whispered.

"It was my-" Rhea stopped. Pleasure? Duty? "I was glad to do it."

Byleth kissed Rhea's neck, dragged her tongue across her skin to lap up some of the blood she'd spilled. Rhea shivered quietly. It was a very... _pleasant_... feeling.

"How often do you need to drink blood?" Rhea asked.

"I don't, I think," said Byleth. "But if I go without blood for more than a Moon, my emotions fade again and I return to my lifeless self. I'd rather not do that."

"So you must feed at least once a Moon, then," Rhea said.

"If I can," said Byleth.

Rhea reached up with an arm that felt surprisingly heavy and gently stroked Byleth's hair. "Then from now on, I shall expect you in my room every Sunday night," she said.


End file.
